Modular child restraint system

ABSTRACT

A modular child restraint system for use in vehicles comprises a base and interchangeable attachable seats where the seats are for different stages of childhood development. The system can further comprise additional bases adapted to other uses such as strollers and infant swings. A common engagement mechanism allows the various seats to be moved from one base to another. One such system comprises a base and a seat configured to rotate relative to one another when engaged. The seat can also lock in a position relative to the base. The base includes a visual indicator to show that the seat is secured to the base.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.60/571,791 filed on May 17, 2004 and titled “Child Car Seat withImprovements,” and U.S. Provisional Application Nos. 60/610,774,60/610,686, 60/611,177, and 60/610,800 each filed on Sep. 17, 2004 andtitled, respectively, “Modular Child Restraint System that InvolvesRotation and Removal,” “Actively Securing Child Restraint Base Interfacethat Amplifies User Leverage,” “Modular Upgradeable Child RestraintSystem,” and “Child Vehicle Restraints;” all five applications areincorporated herein by reference. This application is related to U.S.application Ser. No. ______ titled “Actively Securable Base for aModular Child Restraint System” (Attorney Docket No. PA3123US) and U.S.application Ser. No. ______ titled “Improvements for Child RestraintSystems” (Attorney Docket No. PA3125US), both filed on even dateherewith and incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to the field of transportationsafety and more particularly to child carriers for use in vehicles.

2. Description of the Prior Art

Children's car seats have made automobile travel substantially safer forchildren, however, as most parents are aware, properly installing suchseats is typically difficult and sometimes frustrating. One solution hasbeen to develop modular car seat systems with a base that remainssemi-permanently installed and a seat that can be readily engaged withthe base. With such systems the hard work of installing the base doesnot have to be frequently repeated.

What is lacking, however, is a modular child's car seat system that isupgradeable with different seats that work with the same base, where thedifferent seats accommodate different stages in the child's development.

SUMMARY

The present invention provides a modular child restraint system for usein vehicles. An exemplary modular child restraint system of theinvention comprises a plurality of different seats and a base configuredto be installed in a vehicle such as an automobile, boat, or airplane.Each of the different seats can engage with the base, and each of thedifferent seats is adapted to a different stage of child development.Thus, one seat can be a rear-facing infant seat, another can be atoddler seat, and yet another can be a booster seat.

Conveniently, the modular child restraint system can further comprise asecond base, different than the first base, and that can also be engagedwith the various seats. Examples of different second bases include basesadapted to strollers and swings. Even though the bases are different, acommon engagement mechanism allows the various seats to be moved fromone to another.

Another exemplary modular child restraint system of the inventioncomprises a base and a seat configured to engage the base and to be ableto rotate relative to the base when engaged thereto. The base can beconfigured to attach to a vehicle seat or can be part of a stroller, forexample. In some embodiments the base is permanently installed in avehicle seat, and can be, for instance, factory installed or installedafter-market. In some of these embodiments only an engagement mechanismof the base, such as a base hub, extends above a seat cushion. The seatis configured, in some embodiments, to lock in a position relative tothe base. The base can also comprise a visual indicator configured tochange color in response to the seat being locked in the positionrelative to the base.

Still another exemplary modular child restraint system of the inventioncomprises a base including a base hub having a circumferential lip and aplurality of detents, and a seat including a seat hub configured torotationally engage with the base hub. The seat, in these embodiments,has a retractable latch configured to engage under the lip to secure theseat hub to the base hub, and lock into the detents to prevent rotationof the seat relative to the base. The modular child restraint system canfurther comprise an indicator configured to indicate whether the seathub is rotationally locked with respect to the base hub. In someembodiments the modular child restraint system further comprises fourretractable latches configured to engage under the lip. In some ofthese, only one of the four latches is sized to lock into the detents.

Yet another exemplary modular child restraint system of the inventioncomprises a base including a base hub having two retaining bars, and aseat including a seat hub configured to rotationally engage with thebase hub. The seat hub includes a circumferential lip that engages thetwo retaining bars to secure the seat to the base. The base hub canfurther include a retractable locking pin configured to engage the seathub to prevent rotation of the seat hub relative to the base hub. Theseat hub can further include a pair of cams configured to push theretaining bars outward to disengage the seat hub from the base hub. Thecams can be vertically or horizontally actuated, for example.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of a modular restraint system according toan embodiment of the invention comprising a base and interchangeableattachable seats.

FIG. 2 is a side view of one of the seats of FIG. 1 attached to the basein a rear-facing configuration.

FIG. 3 is a side view of one of the seats of FIG. 1 attached to the basein a forward-facing configuration.

FIG. 4 is a perspective view of the seat of FIG. 2 attached to the baseand rotated to face sideways.

FIG. 5 is a perspective view of a base hub of a base integrated with avehicle seat, according to an embodiment of the invention, projectingabove a seat cushion thereof.

FIGS. 6 and 7 are side views of the seats of FIG. 1 respectively engagedwith a base adapted to a stroller, according to an embodiment of theinvention.

FIGS. 8 and 9 are cross-sectional views of an engagement mechanism,according to an embodiment of the invention, comprising base and seathubs before and after engagement, respectively.

FIGS. 10 and 11A are different perspective views of a base according toan embodiment of the invention.

FIG. 11B is a perspective view of a base according to an embodiment ofthe invention showing a base hub with an alternative locking indicator.

FIG. 11C is a bottom perspective view of a seat with a seat hub thatengages with the base hub of FIG. 11B.

FIG. 12 is a bottom perspective view of a base according to anembodiment of the invention.

FIGS. 13 and 14 are top views of a latch mechanism, according to anembodiment of the invention, for engaging a seat hub with a base hub,respectively showing engaged and disengaged positions.

FIGS. 15 and 16 are, respectively, top and bottom views of a latchmechanism, according to another embodiment of the invention, forengaging a seat hub with a base hub.

FIG. 17 is a perspective view of a cross-section of an engagementmechanism of an embodiment of the invention comprising base and seathubs, prior to engagement.

FIGS. 18-20 are bottom perspective views of the seat hub of theembodiment of FIG. 17, with FIG. 20 showing the base hub partiallydisassembled.

FIG. 21 is a top perspective view of the seat hub of the embodiment ofFIG. 17.

FIG. 22 is a bottom view of the seat hub of the embodiment of FIG. 17,partially disassembled as in FIG. 20.

FIGS. 23 and 24 are top perspective views of the base hub of theembodiment of FIG. 17.

FIG. 25 is a bottom perspective view of the base hub of the embodimentof FIG. 17.

FIG. 26 is a side view of the base hub of the embodiment of FIG. 17.

FIG. 27 is a cross-sectional view of the engagement mechanism of FIG. 17with the base and seat hubs engaged.

FIG. 28 is a perspective view of components of an engagement mechanismaccording to another embodiment of the invention.

FIG. 29 is a schematic representation, including a cross-section throughthe embodiment of FIG. 28, to illustrate the activation thereof.

FIG. 30 is an exemplary base hub according to another embodiment of theinvention.

FIG. 31 is a bottom perspective view of components of an engagementmechanism according to still another embodiment of the invention.

FIGS. 32 and 33 are cross-sectional views of the mechanism of FIG. 31engaged and disengaged, respectively.

FIG. 34 is a perspective view of an engagement mechanism according toyet another embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides modular child restraint systems for usein vehicles such as automobiles, aircraft, boats, buses, and so forth.The modular restraint system comprises a base and interchangeableattachable seats. The base serves as the primary interface between theattached seat and a vehicle seat and is designed to be left attachedthereto. Each seat is intended to hold a child at a different stage ofdevelopment and is typically provided with a restraint mechanism such asa harness. One advantage of the modular design is that the same base canbe used to support seat that are adapted for different stages ofchildhood such as for infants, toddlers, and older children. Thus, as achild grows, only the seat needs to be upgraded.

Additionally, the invention provides for a system in which the same seatcan be attached to bases adapted for different purposes such as a basefor a vehicle seat, a base for a stroller, and so forth. Further theinvention provides an advantageous engagement mechanism as an interfacebetween the seat and base. With this engagement mechanism the seat canbe rotated relative to the base and locked in essentially anyorientation.

FIG. 1 illustrates a modular restraint system comprising a base 100 andinterchangeable attachable seats 110 and 120. In some embodiments thebase 100 is actively expandable as described in U.S. application Ser.No. ______ (Attorney Docket No. PA3123US) which is incorporated byreference herein. Other attributes of various embodiments of the base100 that are described in the aforementioned application include ease ofinstallation, and foldability for portability. Seat 110 is an embodimentof an infant carrier, while seat 120 is an embodiment of a toddler orconvertible seat. A convertible seat is one that is adjustable toaccommodate a wide range of child sizes and weights so that the sameseat can accommodate a growing child for many years. It will beappreciated that the seats 110 and 120 are merely two examples ofpossible seats that can be attached to the base 100. Another example isa booster seat, for instance.

FIGS. 2 and 3 show, respectively, the seats 110 and 120 engaged with thebase 100. In FIG. 2 the seat 110 is in a rear-facing configuration thatis recommended for babies and infants. In FIG. 3 the seat 120 isoriented in a forward-facing configuration that is suitable for olderchildren with sufficient neck strength. As illustrated by FIG. 4, insome embodiments a seat such as seat 120 can be positioned on the base100 in other orientations as well. While a side-facing orientation maynot be desirable in a moving automobile for safety reasons, it will beappreciated that the ability to choose orientations other than forwardand rear-facing can be quite desirable in other situations, for example,in a parked automobile, on an airplane, and so forth. Engagementmechanisms that allow for such rotational freedom are discussed in moredetail below.

FIG. 5 illustrates an embodiment of the invention in which a base ofmodular child restraint system is integral with a vehicle seat 500 sothat only a base hub 510 of an engagement mechanism projects above theseat cushion. The base can be either factory installed or anafter-market add-on. Similarly, the base can be integrated with otherstructural components of a vehicle such as a folding armrest.

As described above, one base can be used with multiple seats that areadapted to different stages of childhood. Additionally, the inventionalso provides for the same seat to be used with multiple bases adaptedto different vehicles or uses. FIGS. 6 and 7 illustrate the seats 110and 120, respectively, engaged with a base 600 adapted to another typeof vehicle, in this case a stroller. It will be apparent that a base ofthe invention can likewise be adapted to other uses such as an infantswine, a high chair, and so forth.

As previously noted, embodiments of the engagement mechanism that serveas the interface between the various bases and seats of the modularsystem provide for easy attachment and disengagement of the two matingcomponents, as well as rotation of the seat relative to the base. FIGS.8 and 9 schematically illustrate an embodiment of an engagementmechanism in cross-section before and after being engaged, respectively.In FIG. 8 a base hub 800 of the engagement mechanism includes a recess810 for receiving a seat hub 820 of the engagement mechanism. As shown,the recess 810 and seat hub 820 are shaped so that the seat hub 820nests snuggly in the recess 810 when the two hubs 800, 820 are engaged(FIG. 9).

To prevent the two hubs 800, 820 from accidentally separating, the seathub 820 includes spring-loaded latches 830 that project into acircumferential groove 840 and under a lip 850 of the base hub 800. Eachlatch 830 includes an engaging face 860 that helps guide the seat hub820 into the recess 810. Forcing the seat hub 820 into the recess 810pushes the latches 830 laterally against the force of the spring untilthe latches 830 pass the lip 850 and are driven by the spring into thegroove 840. Each latch 830 also includes a retaining face 870 that matesagainst an underside face 880 of the lip 850.

It can be seen that once the two hubs 800, 820 are engaged, the seat hub820 is free to rotate within the grove 840 of the base hub 800. It isnoted that although two latches 830 share a common spring 890 in FIGS. 8and 9, each latch 830 can alternately be fitted with a dedicated springso that the latches operate independently for greater security. It willalso be appreciated that the spring can be a coiled spring, a leafspring, or some other device that provides a similar restorative force.A mechanism (not shown) is configured to fully retract the latches 830so that the seat hub 820 can be removed from the base hub 800.Embodiments of this mechanism are discussed below.

FIG. 10 shows a perspective view of a base hub 1000 of a base 1010 foruse with a vehicle seat. The base hub 1000 includes a groove 1020 forreceiving latches of a seat hub (not shown). Within the groove 1020 areseveral detents 1030 at intervals around the circumference of the groove1020. When the seat hub is engaged with the base hub 1000 and rotatedrelative thereto, the latches of the seat hub engage with the detents1030 to lock the seat hub relative to the base hub 1000 in a particularorientation. Where the seat hub includes two oppositely disposed latchesas in FIGS. 8 and 9, the detents 1030 are also oppositely disposedaround the groove 1020. Accordingly, eight detents 1030 at 45° intervalswill allow the base hub to lock in eight different orientations so thatthe attached seat can assume eight different orientations.

Some embodiments of the invention employ two, three, or four latches onthe seat hub. In some of these embodiments the latches have differentwidths so that some latches are more narrow than the others. In theseembodiments the detents on the base hub are sized to only accommodatethe more narrow latch or latches. In this way, for example, aforward-facing seat with four latches can be made to rotate through 360°but only lock in the forward-facing orientation. It is also noted thatin some embodiments the seat hub is configured with the groove anddetents while the base hub includes the latches.

FIG. 10 also illustrates a locking indicator 1040 on the base 1010. Thelocking indicator 1040 can be configured to change color, for example,when the seat hub is engaged and disengaged from the base hub 1000 orrotated into or out of a locked orientation. In one embodiment thelocking indicator 1040 turns green when the seat hub is engaged andlocked with the base hub 1000, and changes to red when the seat hub isunlocked. Thus, a person engaging the seat hub with the base hub 1000has a visual cue that the two are properly connected.

FIG. 11A shows a perspective view of an exemplary base 1100 to betterillustrate one possible embodiment of a locking indicator 1110 andassociated mechanism. The base 1100 includes a base hub 1120 having adetent 1130. In the detent 1130 is an actuator 1140 that is pushed by alatch of the seat hub when the seat hub is engaged. A spring-loadedmechanical linkage (not shown) within the base hub 1120 connects theactuator 1140 to a plastic piece beneath a window of the lockingindicator 1110. The plastic piece has two colored strips thereon, one toindicate the unlocked state, and the other to indicate the locked state.The mechanical linkage keeps the strip for the unlocked state displayedin the window unless a latch pushes the mechanical linkage far enoughthat the other strip becomes visible.

In some embodiments, the latches of the seat hub are designed, asdescribed above, so that only a designated latch will fit the detent1130. Thus, the locking indicator 1110 will only activate when thecorrect seat orientation is achieved. It will be understood that othermechanical and non-mechanical alternatives can also be employed. Forinstance, the locking indicator can be an LED and/or can include a soundgenerator to produce an audible indicator. Such an indicator can beactuated mechanically, electrically, or magnetically. Some embodimentsinclude two indicators, one to show that the base and the hub arerotationally engaged, and a second to show that the two are locked toprevent rotation.

Another embodiment of the present invention employs two lockingindicators as shown in FIGS. 11B and 11C. FIG. 11B is a top perspectiveview of a base 1150 and FIG. 11C is a bottom perspective view of a seat1155 according to this embodiment. The base 1150 includes a base hub1160 that has two locking indicators 1165 (one hidden in FIG. 11B) thatare independently activated when spring-loaded buttons 1170 of the basehub 1160 engage matching recesses 1175 in a seat hub 1180 of the seat1155.

FIG. 12 shows a bottom perspective view of a seat 1200 including a seathub 1210 and release lever 1220. A cable (not shown) runs through thebody of the seat 1200 to the seat hub 1210 and is coupled to latches1230. Activating the release lever 1220 retracts the latches 1230 sothat the seat hub 1210 can be disengaged from the base hub. Furtherdetail relating to embodiments for retracting the latches 1230 isdescribed below.

FIGS. 13 and 14 illustrate one embodiment of a mechanism that isactivated by a cable for retracting the latches of a seat hub. FIG. 13shows the mechanism 1300 at rest. The mechanism 1300 comprises two leverarms 1310, 1320 set at 90° to each other that are attached together at apivot point 1330. Links 1340 join the lever arms 1310, 1320 to latches1350. In FIG. 13 the latches 1350 are forced outward by a spring 1360attached to lever arm 1310.

In FIG. 14 a force is applied to a cable 1400 attached to lever arm1320. The cable 1400 can be actuated, for example, by a release lever asdescribed above. The force on the cable 1400 rotates the two lever arms1310, 1320 against the tension of the spring 1360, causing the spring1360 to stretch. Rotating the two lever arms 1310, 1320 causes the links1350 to pull the latches 1350 inward towards the pivot point 1330. Oncethe latches 1350 are retracted in this way, the seat hub can disengagefrom the base hub. Releasing the force on the cable 1400 allows thespring 1360 to restore the mechanism 1300 to the state shown in FIG. 13.

FIGS. 15 and 16 show top and bottom views of an alternative embodimentto the mechanism 1300 described with respect to FIGS. 13 and 14.Mechanism 1500 includes four latches 1510 instead of the three latches1350 employed by mechanism 1300. The mechanism 1500 also includes asupport plate 1520 to which the latches 1510 are slidably attached to anunderside thereof. Additionally, mechanism 1500 includes a single lever1530 disposed above the support plate 1520. The lever 1530 attaches to acable (not shown) which is configured to pull the lever 1530 as in theprevious embodiment. The lever 1530 attaches to a shaft 1540 thatprojects through the support plate 1520 and engages the center of a hub1600 disposed below the support plate 1520. The hub 1600 engages spokes1610 that connect to the latches 1510.

In operation, applying a force to the cable moves the lever 1530, thelever 1530 turns the shaft 1540 which rotates the hub 1600 and retractsthe latches 1510. Releasing the cable then allows the mechanism 1500 toreturn to the state shown in FIGS. 15 and 16. It is also noted that alatch 1510′ is more narrow than the other three latches 1510 inaccordance with the discussion above. It is also noted that in FIG. 15the latches 1510 are retracted while in FIG. 16 the latches 1510 arefully extended.

Also not shown in FIGS. 15 and 16 is the means for restoring themechanism 1500 to the state shown in FIGS. 15 and 16. One alternative isto attach a spring to the lever 1530 to pull the lever 1530 so as tocounteract the force exerted by the cable. Another alternative is toconfigure each latch 1510 with an independent spring on the underside ofthe support plate 1520. This alternative provides an additional degreeof security.

FIGS. 17-27 illustrate yet another embodiment of an engagement mechanismthat allows for rotation. FIG. 17 shows this engagement mechanism in aperspective view of a cross-section of a base 1700 including a base hub1705, and a seat 1710 including a seat hub 1715. To better understandhow the hubs 1705 and 1715 engage, disengage, and rotate relative to oneanother, the components of both hubs 1705 and 1715, and their operation,will first be discussed separately. It will be appreciated that althoughthe components labeled as the base 1700 and seat 1710 are discussedherein as if integral with the overall structures of the base and seat(e.g. base 100 and seat 120 in FIG. 1), the base 1700 and seat 1710 canalso be subassemblies that include the hubs 1705 and 1710 and that areultimately bolted, welded, or otherwise permanently attached to the baseand seat.

FIGS. 18 and 19 show bottom perspective views from two different anglesof the seat 1710 and seat hub 1715 (i.e., flipped upside-down withrespect to the perspective shown in FIG. 17). From FIG. 19 it can beseen that seat hub 1715 includes two cams 1900, one partially visibleand the other disposed 180° away and hidden from view by retaining plate1910. FIG. 20 shows another perspective view of the seat 1710 and seathub 1715 with the retaining plate 1910 removed to better illustrate thecams 1900.

FIG. 21 shows a top view of seat 1710. A 4-bar mechanism of the seat hub1715 comprises two links 2100 each joined to the two cams 1900 throughgrooves cut into a center plate 2110. The 4-bar mechanism also comprisesfour rods (not shown) that connect the ends 2010 of the cams 1900 to theends 2120 of the links 2100 and are constrained to move in the groovesin the center plate 2110. More specifically, the rods connect oppositeends 2120 of each link 2100 to each of the two cams 1900, and connectopposite ends 2010 of each cam 1900 to each of the two links 2100. Thus,the links 2100 and cams 1900 are interconnected and move in unison.

Each link 2100 is also attached to a cable 2130 for actuating the 4-barmechanism. The other end of the cable 2130 can be attached, for example,to a release lever on the seat 1710. Because the 4-bar mechanism movesin unison, pulling on either cable 2130 is sufficient to move both links2100 and both cams 1900. As will be described below, actuating the cams1900 is necessary to disengage the seat hub 1715 from the base hub 1705.It is noted that in FIGS. 20 and 21 the 4-bar mechanism is in the fullyactuated position.

FIG. 22 shows a bottom view of the seat 1710 and seat hub 1715 with theretaining plate 1910 removed to illustrate the cams 1900 in the fullynon-actuated position. Though not illustrated, it will be understoodthat the seat hub 1715 includes one or more cam springs configured tohold the cams in the fully non-actuated position. Thus, pulling on thecable 2130 works against the cam spring. In this way the amount of forcenecessary to disengage the seat hub 1715 from the base hub 1705 can beset by the strength of the cam spring to prevent accidentaldisengagement.

Turning now to the base 1700 and the base hub 1705, FIG. 23 shows thatthe base hub 1705 includes two retaining bars 2300 that retain the seathub 1715 when the two hubs 1705, 1715 are engaged, as described below.Each retaining bar 2300 is supported at either end by a lever arm 2310.Each lever arm 2310 is pivotally attached to the base hub 1705.Accordingly, the two retaining bars 2300 are configured to pivot aroundthe pivot points of attachment 2320 of the lever arms 2310. The base hub1705 also includes two slots 2330 within which the retaining bars 2300move when pivoted. A spring 2340 between lever arms 2310 of the tworetaining bars 2300 (a second spring can also be symmetrically locatedon the opposite side of the base hub 1705) holds the retaining bars 2300within the slots 2330.

FIG. 24 shows the same base hub 1705 as in FIG. 23, but with theretaining bars 2300 pivoted outward against the force of the spring2340. As described below, the retaining bars 2300 engage behind theretaining plate 1910 of the seat hub 1715 to secure the seat hub 1715 tothe base hub 1705. Base hub 1705 also comprises a locking pin 2350 thatengages the seat hub 1715 to prevent the seat hub 1715 from rotatingwithin the base hub 1705 unless the locking pin 2350 is withdrawn, asalso described further below.

FIGS. 25 and 26 show, respectively, a bottom perspective view and a sideview of the base 1700 and base hub 1705. It can be seen from thesedrawings that rotation levers 2600 pivotally engage the locking pin 2350from the underside of the base hub 1705. Each rotation lever 2600 isalso pivotally connected to the hub 1700 by a spring-loaded pivotmechanism 2610 that keeps the rotation levers 2600 and locking pin 2350in the position shown. Pulling up on either rotation lever 2600, asindicated, draws the locking pin 2350 down so that the seat hub 1715 canrotate. For clarity, the spring 2340 has been omitted from FIGS. 25 and26.

With reference now to FIG. 27, which shows a cross-sectional view of thebase hub 1705 and the seat hub 1715 fully engaged, and with referenceagain to FIG. 17, the engagement, disengagement, and rotation of theseat 1710 and base 1700 can now be fully explained. To engage the basehub 1705 with the seat hub 1715, the seat 1710 is positioned over thebase 1700 so that the retaining plate 1910 of the seat hub 1715 iscentered over the base hub 1705. The retaining plate 1910 includes a liphaving a beveled lower edge that pushes the two retaining bars 2300laterally against the force of the spring 2340 (not shown in FIGS. 17and 27) as the seat hub 1715 is forced down against the base hub 1705.Once the widest point of the retaining plate 1910 passes the retainingbars 2300, the retaining bars 2300 are pulled back by the spring 2340 toengage behind the lip of the retaining plate 1910 as shown in FIG. 27.Thus, the retaining bars 2300 help to pull the seat hub 1715 down intothe base hub 1705 and come to rest against the cams 1900.

It will be apparent that the seat hub 1715 can be engaged in this waywith the base hub 1705 in any rotational orientation, as once engaged,the two are generally free to rotate with respect to one another.However, the retaining plate 1910 also includes a recess 2700 that canengage the locking pin 2350 to stop the rotation. As described above,pulling up on either rotation lever 2600 will draw the locking pin 2350down out of the recess 2700 so that the seat hub 1715 can again rotate.The circumferential position of the locking pin 2350 is chosen so thatwhen the locking pin 2350 engages the recess 2700 the seat 1710 is in adesired orientation relative to the base 1700. In this way, for example,an infant seat 110 (FIG. 1) will lock in the rear-facing orientation. Itwill be understood that more than one recess 2700 can be used to providemore than one locked position.

To disengage the two hubs 1705 and 1715, the retaining bars 2300 must bepushed out from behind the lip of the retaining plate 1910 so that theseat hub 1715 is free to be removed from the base hub 1705. This isaccomplished by the cams 1900 which are actuated by pulling on a cable2130 (FIG. 21; not shown in FIGS. 17 and 27) as discussed above. Whenthe cams 1900 are fully activated, as shown in FIG. 20, the cams 1900push the retaining bars 2300 beyond the retaining plate 1910.

FIGS. 28-30 illustrate still another embodiment of the invention havingvertically actuated cams. FIG. 28 shows a perspective view of thisembodiment. In FIG. 28 retaining bars 2800 of a base hub (not otherwiseshown) such as base hub 1705 described above are engaged behind aretaining plate 2810 of a seat hub (also not otherwise shown) such asseat hub 1715. Two vertically actuated cams 2820 of the seat hub areshown in the fully actuated position. When actuated as shown, rotatingthe seat hub causes the vertically actuated cams 2820 to push theretaining bars 2800 out from behind the retaining plate 2810.

FIG. 29 shows a cross section through a seat hub 2900 of thisembodiment. As shown, the vertically actuated cams 2820 when notactuated are retracted to allow unimpeded rotation of the seat hub 2900within the base hub. Only when the vertically actuated cams 2820 areactuated (dotted outline) and pushed downward will rotation of the seathub 2900 cause the seat hub 2900 to disengage from the seat hub. FIG. 29also schematically shows a mechanism for actuating the verticallyactuated cams 2820. Here, a user pulls up on a release lever 2910attached to a handle of the seat to which the seat hub 2900 is attached.A cable 2920 attached to the release lever 2910 drives a mechanism (notshown) that forces the vertically actuated cams 2820 downward. A returnspring (not shown) provides a restorative force that otherwise keeps thevertically actuated cams 2820 in the non-actuated position and gives aresistance to the mechanism so that a threshold amount of force must beapplied to the cable 2920 to move the vertically actuated cams 2820.

FIG. 30 shows a photograph of a prototype of another embodiment of abase hub 3000. Although base hub 3000 is discussed in connection withthe seat hub 2900 embodiment of FIG. 29, it will be understood that itwill also work with seat hub 1715, discussed above. In this embodimentthe retaining bars 3010 are not situated on the ends of lever arms thatare coupled by a spring, as in base hub 1705, but are instead directlycoupled by springs 3020 (one spring 3020 is hidden in FIG. 30). Asabove, the retaining bars 3010 are constrained to move within grooves3030 and otherwise function to engage the retaining plate 2910 asdescribed previously.

FIGS. 31-33 show still another embodiment. In this embodiment aretaining plate is attached to a base rather than to a seat as in thepreviously described embodiment, however, this embodiment is not limitedto this arrangement and can also be implemented with the retaining plateattached to the seat. FIG. 31 shows a bottom perspective view of aretaining plate 3100 attached to a base (not shown), and a pair ofretaining members 3110 slidably attached to a seat (also not shown) andconfigured to engage the retaining plate 3100. A pair of springs 3120,for example, provide a restorative force to keep the retaining members3110 mated together. As shown, each retaining member 3110 includes asemi-circular recess so that when mated together, the retaining members3110 form an aperture with a beveled surface. The retaining plate 3100has a matching beveled surface, as can be seen more readily in FIGS. 32and 33 which are cross-sections through the retaining plate 3100 andretaining members 3110.

When the seat is engaged with the base, in this embodiment, the apertureformed between the retaining members 3110 is positioned over theretaining plate 3100 and the seat is forced downward so that the beveledsurface of the retaining plate pushes against the beveled surfaces ofthe retaining members 3110 and forces the retaining members 1110 apartagainst the force of the springs 3120. After a lip 3130 of the retainingplate 3100 passes the retaining members 3110, the retaining members 3110close behind the lip 3130, as shown in FIG. 32. It can be seen from FIG.32 that the retaining members 3110 engage the lip 3130 to prevent theretaining plate 3100 from being withdrawn, yet the retaining plate 3100is free to rotate within the aperture. In one embodiment, shown in FIG.33, force applied to a pair of cables 3300 attached to the retainingmembers 3110 pulls the retaining members 3110 apart to release theretaining plate 3100.

A further embodiment is shown in FIG. 34. This embodiment resembles alock and key and is deemed to be passive in that it does not includemoving parts. As can be seen from FIG. 34, either of the seat or thebase is fitted with a retaining plate 3400 and the opposing component isfitted with a receiving chamber 3410 having an aperture 3420 shaped tomatch the specific shape of the retaining plate 3400. The retainingplate can only be inserted or removed through the aperture 3420 when theretaining plate 3400 is properly aligned. Once engaged, the retainingplate 3400 can rotate freely within the receiving chamber 3410.

Here, the symmetry of the shape of the retaining plate 3400 determineshow many orientations the seat can be in, relative to the base, whenengaging and disengaging. A complete lack of symmetry means that the twocan only be engaged and disengaged in one position, whereas the two-foldsymmetry of the example in FIG. 34 allows for two positions. Forexample, with the rear-facing infant seat 110 (FIG. 1), the seat wouldhave to be oriented either 90° clockwise or counter-clockwise from therear-facing orientation (i.e., facing either passenger door) in order toengage or disengage.

In the foregoing specification, the invention is described withreference to specific embodiments thereof, but those skilled in the artwill recognize that the invention is not limited thereto. Variousfeatures and aspects of the above-described invention may be usedindividually or jointly. Further, the invention can be utilized in anynumber of environments and applications beyond those described hereinwithout departing from the broader spirit and scope of thespecification. The specification and drawings are, accordingly, to beregarded as illustrative rather than restrictive. It will be recognizedthat the terms “comprising,” “including,” and “having,” as used herein,are specifically intended to be read as open-ended terms of art.

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(canceled) 24: A child restraint system comprising: a baseincluding a base hub having a circumferential lip and at least onedetent; and a seat including a seat hub configured to rotationallyengage with the base hub, wherein the seat hub comprises at least oneretractable latch configured to: engage under the circumferential lip ofthe base hub to secure the seat hub to the base hub, and lock into atleast one of the at least one detents to prevent rotation of the seatrelative to the base. 25: The child restraint system of claim 24,wherein the seat further comprises a release lever associated therewithoperable to move the retractable latch for disengagement of the seat hubfrom the base hub. 26: The child restraint system of claim 24, furthercomprising an indicator configured to indicate whether the seat hub isrotationally locked with the base hub. 27: The child restraint system ofclaim 24, further comprising a visual indicator configured to changecolor in response to the seat being rotationally locked with the base.28: The child restraint system of claim 24, further comprising tworetractable latches configured to engage under the circumferential lip.29: The child restraint system of claim 24, wherein the base isconfigured to be attached to a vehicle seat. 30: The child restraintsystem of claim 24, wherein the base is part of a stroller. 31: Thechild restraint system of claim 24, further comprising a second seatconfigured to detachably engage the base and to be able to rotaterelative to the base when engaged thereto, wherein the seats are adaptedto different stages of child development. 32: A child restraint systemcomprising: a base; and a seat configured to rotationally engage thebase, wherein the seat is separable from the base when a release leverassociated with the seat is activated. 33: The child restraint system ofclaim 32, wherein the seat and base are further configured torotationally lock in at least one rotational position. 34: The childrestraint system of claim 33, wherein the seat and hub are furtherrotationally unlocked in response to activating the release lever. 35:The child restraint system of claim 32, wherein the seat and base arefurther configured to rotationally lock in at least two rotationalpositions. 36: The child restraint system of claim 35, wherein the seatand hub are further rotationally unlocked in response to activating therelease lever. 37: The child restraint system of claim 32, wherein thebase includes a base hub operable to engage a seat hub associated withthe seat. 38: The child restraint system of claim 32, wherein: the baseincludes a base hub having a circumferential lip and at least onedetent; and the seat includes a seat hub configured to rotationallyengage with the base hub, wherein the seat hub comprises at least oneretractable latch configured to engage under the circumferential lip ofthe base hub to secure the seat hub to the base hub, and lock into atleast one of the at least one detents to prevent rotation of the seatrelative to the base. 39: The child restraint system of claim 38,further comprising at least two retractable latches configured to engageunder the circumferential lip. 40: The child restraint system of claim32, wherein: the base includes a base hub having two retractableretaining bars; and the seat includes a seat hub configured torotationally engage with the base hub and having a circumferential lipthat engages the two retaining bars to secure the seat to the base. 41:The child restraint system of claim 40, wherein the seat hub furthercomprises at least one cam configured to push at least one of the tworetractable retaining bars to disengage the seat hub from the base hub.42: A child restraint system comprising: a seat having a seat hubassociated therewith configured to rotationally engage with a base hub,the seat hub having at least one retractable latch configured to securethe seat hub to the base hub, wherein the at least one retractable latchis movable in response to activating a release lever associated with theseat for disengaging the seat hub from the base hub. 43: The childrestraint system of claim 42, further comprising at least tworetractable latches. 44: The child restraint system of claim 42, whereinthe at least one retractable latch is further configured to engage withat least one feature of the base hub to restrict rotation of the seatrelative to the base. 45: The child restraint system of claim 42,wherein the release lever is located with a handle associated with theseat. 46: A child restraint system comprising: a base having a base hubassociated therewith configured to rotationally engage with a seat hub,the base hub having a circumferential lip configured for engagement by aseat hub having at least one retractable latch, the base hub furtherhaving at least one feature for engaging the at least one retractablelatch to prevent rotation of the seat hub relative to the base hub,wherein the seat hub and base hub are separable when the retractablelatch is retracted. 47: A child restraint system comprising: a basehaving a base hub associated therewith configured to rotationally engagewith a seat hub, the base hub having at least one retractable retainingbar operable to engage a feature of a seat to secure the seat to thebase. 48: The child restraint system of claim 47, wherein the at leastone retractable retaining bar is operable to engage a circumferentiallip associated with the seat.